<!DOCTYPE html >
<html>

<head>
  <meta charset="UTF-8" />
  <title>Hello World</title>
  <script src="https://unpkg.com/react@16/umd/react.development.js"></script>
  <script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
  <script src="https://unpkg.com/babel-standalone@6.15.0/babel.min.js"></script>
</head>

<body>
  <div id="root"></div>
  <script type="text/babel">


    function formatName(user) {
       return user.firstName+ ' ' + user.lastName; 
      } 
      const user = { 
        firstName: 'Bill', lastName: 'Gates'
    }; 
    const element =
    <h1>
      hello, {formatName(user)}!
    </h1>

    ReactDOM.render( element, document.getElementById('root') )
  </script>
  <!--
          Note: this page is a great way to try React but it's not suitable for production.
          It slowly compiles JSX with Babel in the browser and uses a large development build of React.
    
          To set up a production-ready React build environment, follow these instructions:
          * https://reactjs.org/docs/add-react-to-a-new-app.html
          * https://reactjs.org/docs/add-react-to-an-existing-app.html
    
          You can also use React without JSX, in which case you can remove Babel:
          * https://reactjs.org/docs/react-without-jsx.html
          * https://reactjs.org/docs/cdn-links.html
        -->
</body>

</html>